Laminated sprocket assembly

ABSTRACT

A laminated sprocket assembly is provided formed of a plurality of layers that are connected together. Each of the layers is a stamped sheet metal layer having a plurality of spaced apart teeth located around a periphery thereof. The teeth in the plurality of connected layers are aligned. At least one of voids, channels, openings, or recesses are located in or between at least some of the layers for receiving and holding lubricating oil. This reduces noise and wear.

INCORPORATION BY REFERENCE

This application is a divisional application of U.S. patent applicationSer. No. 14/307,895, filed Jun. 18, 2014, which claims the benefit ofU.S. Provisional Application No. 61/844,094, filed Jul. 9, 2013, whichare both incorporated by reference as if fully set forth.

FIELD OF INVENTION

The present invention relates to a sprocket assembly and in particularto a laminated sprocket assembly.

BACKGROUND

Laminated sprocket assemblies formed with a plurality of layers that arebonded or welded together are known. For example, U.S. Pat. No.5,074,406 teaches such a laminated sprocket in which each of the layersincludes a central opening for fitting onto a drive shaft. Teeth orother driving surfaces are formed around the periphery of the layers andthe layers can be stacked with spacers located between the layers sothat the teeth are spaced apart for example to carry a chain conveyor orbelt conveyor having pockets in which the teeth of the laminatedsprocket are engaged.

In the field of automotive engines, sprockets are used in connectionwith timing chains and timing drives and for various other purposes.Generally such sprockets have been formed as a solid machined part or asintered part due to the high speeds and loads with which such sprocketsoperate. However, such machined or sintered sprockets are associatedwith higher costs.

It would be desirable to provide a laminated sprocket which would besuitable for use in connection with high speed equipment, andparticularly for use as timing chain sprockets and/or other sprocketsused in connection with internal combustion engines.

SUMMARY

A laminated sprocket assembly is provided formed of a plurality oflayers that are connected together. Each of the layers is a stampedsheet metal layer having a plurality of spaced apart teeth locatedaround a periphery thereof. The teeth in the plurality of connectedlayers are aligned. At least one of voids, channels, openings, orrecesses are located in or between at least some of the layers forreceiving and holding lubricating oil.

Preferably, each of the stamped or punched sheet metal layers includes ashaft opening. Additional aligned openings may be defined in each of thelayers in a position spaced apart from the shaft opening and the teethwhich can be used to contain lubricating oil. In one preferred aspect,voids are located between the sheet metal layers used to form thelaminated sprocket assembly and lubricating oil is retained in and/orseeps through these layers to provide lubrication at the surfaces of theteeth. Lubricant can be received through the aligned openings located inthe layers at a position spaced apart from the shaft opening and teeth.

Additionally, it is possible to have recesses located in at least someof the layers in the face, flank, or undercut (generally referred to asthe tooth side) of each of the teeth with these recesses preferablybeing formed by a radius, and the layers on either side of the layerswith the recesses including teeth having sides without recesses in orderto form pockets for retaining lubricating oil. This provides for noisereduction and lubrication.

In another aspect, each of the layers includes a shaft opening, and atleast some of the layers include a channel that extends from the shaftopening to a periphery of the laminated sprocket assembly. In oneaspect, the channel can be defined by a slot extending through the layerwith the slot preferably being punched in the sheet metal layer as eachlayer is being formed. Preferably, the layers adjacent to the slot aresolid, at least in the area of the slot, in order to define a confinedchannel. A plurality of channels is provided that preferably extendgenerally radially and are spaced apart in a peripheral direction.Preferably, each of the channels ends at an opening in a side of one ofthe teeth so that oil can be fed from the shaft upon which the laminatedsprocket assembly is mounted through the channels to the teeth where achain is engaged. The openings of the channels are preferably axiallyand peripherally spaced apart from one another so that several or all ofthe teeth include an opening for a lubrication channel.

It is also possible for one of the channels to be defined by slots oftwo adjacent ones of the layers, for example with the slots in one ofthe layers extending only part way from the shaft opening toward theteeth and the slots in the adjacent layer extending from the positionpartway between the shaft opening and the teeth to the openings in theteeth surfaces.

One or more of the above features can be combined in order to provide alaminated sprocket assembly that includes a feature to retain or providelubrication in order to provide noise reduction and reduced wear.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary and the following detailed description will bebetter understood when read in conjunction with the appended drawings,which illustrate a preferred embodiment of the invention. In thedrawings:

FIG. 1 is a perspective view of a first embodiment of a laminatedsprocket assembly according to the invention.

FIG. 2 is an enlarged detail showing the teeth of the laminated sprocketassembly of FIG. 1.

FIG. 3 is a perspective view of a single layer used in forming alaminated sprocket assembly.

FIG. 4 is a plan view of the single layer shown in FIG. 3.

FIG. 5 is an enlarged view showing a preferred tooth configuration ofthe layer in FIG. 4.

FIG. 6 is an enlarged perspective view showing a second embodiment of asprocket assembly according to the invention with recesses located in aside of the teeth.

FIG. 7 is a partial plan view showing two layers used to form thesprocket assembly of FIG. 6 with the top layer including recesses beingplaced upon an adjacent layer that does not include recesses in thesides of each of the teeth.

FIG. 8 is a partial plan view showing a layer having teeth with recessesas used in the sprocket assembly of FIG. 6.

FIG. 9 is an enlarged view showing pockets formed between the recessesand the chain links.

FIG. 10 is a plan view showing a layer in which the teeth includerecesses.

FIG. 11 is a perspective view of a third embodiment of a laminatedsprocket assembly according to the invention.

FIG. 12 is a partial perspective view showing a partially assembledsprocket assembly with an oil feed channel in one layer extendingbetween the shaft opening and the teeth.

FIG. 13 is a plan view showing one layer used in the sprocket assemblyof FIG. 11 having the oil feed channel that is placed on an adjacentlayer that does not include the oil feed channel.

FIG. 14 is a plan view showing a plurality of oil feed channels locatedwithin the sprocket assembly shown in FIG. 11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “front,” “rear,” “upper” and “lower”designate directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” refer to directions toward and awayfrom the parts referenced in the drawings. “Axially” refers to adirection along the axis of a shaft. A reference to a list of items thatare cited as “at least one of a, b, or c” (where a, b, and c representthe items being listed) means any single one of the items a, b, or c, orcombinations thereof. The terminology includes the words specificallynoted above, derivatives thereof and words of similar import.

Referring now to FIGS. 1-5, a first embodiment of a laminated sprocketassembly 10 is shown. The laminated sprocket assembly 10 includes aplurality of layers 12 that are connected together, with each of thelayers 12 being a stamped or punched sheet metal layer having aplurality of spaced apart teeth 14 located around a periphery thereof.Stamping or punching are used synonymously herein, and allow the layersto be produced cheaply. The teeth 14 of the plurality of layers 12 to beconnected are aligned. Preferably a shaft opening 11 extends througheach of the layers and is adapted to receive a shaft when the sprocketassembly is installed, for example on a camshaft of an internalcombustion engine. According to the first preferred embodiment of thelaminated sprocket assembly 10, the aligned layers 12 are connectedtogether by bonding, welding or any other suitable means.

In the first preferred embodiment of the laminated sprocket assembly 10,voids 16 are located in or between at least some of the layers 12 forreceiving lubricating oil. These voids indicated as 16 in FIG. 2 can bethe result of unevenness in the layers generated by the stamping processor can be specifically designed through unevenness introduced in thestamping dies used to form the sheet metal layers 12. This providessmall gaps for residual oil to be retained. In order to feed lubricatingoil to these small residual gaps, it is also possible to provideopenings 18 for lubrication to penetrate into the laminated sprocketassembly 10 as shown in FIGS. 3 and 4. Here, a single layer 12 is shownwhich can be used in the embodiment of FIG. 1 which is shown without theopenings 18. The profile of the teeth 14 is adapted to the particularapplication for use with a chain of a particular design. Depending uponthe application, steel sheet metal is utilized which can be hardened.

Referring now to FIGS. 6-10, a second embodiment of a laminated sprocketassembly 30 is shown. The laminated sprocket assembly 30 is similar tothe laminated sprocket assembly 10 and includes a shaft opening 31,shown in FIG. 10, as well as teeth 34, located around a periphery of thelayers 32, 33 that are laminated together in order to form the sprocketassembly 30. In the laminated sprocket assembly 30, recesses 40 arelocated in at least some of the layers 33, preferably in one or bothsides 35 of each of the teeth 34. The recesses 40 are preferably formedby a radius. However, other shapes could be utilized. Preferably, thelayers 32 on either side of the layers 33 with the recesses 40 includeteeth 34 having sides 35 without the recesses. Preferably, the layer 33with the recesses 40 is located as every second, third, fourth, or fifthlayer in the sprocket 30, with the remaining layers 32 not havingrecesses so that a series of pockets 44 are spaced apart across theaxial surface of each tooth 34. As shown in FIGS. 6 and 8, openings 38can also be provided in a position spaced apart from the shaft opening31 and the teeth 34. These can be used in order for lubrication to beintroduced into the laminated sprocket assembly 30 which can travelthrough the voids 36 between layers radially outwardly due tocentrifugal force as the sprocket 30 turns to lubricate the chaincontact surfaces of the teeth 34. The recesses 40 allow for residual oilto be held on the tooth surface.

As shown in FIG. 9, the pockets 44 formed by the recesses 40 provide anarea for lubricating oil to be held between the tooth surfaces and achain link 42 when the laminated sprocket assembly 30 is in use. Thisprovides a lubricant holding area for cushioning and sound deadening aswell as lubrication in use.

Referring now to FIGS. 11-14, a third embodiment of a laminated sprocketassembly 50 is shown. The laminated sprocket assembly 50 is similar tothe laminated sprocket assemblies 10 and 30 in that it is formed from aplurality of layers 52, 53 which are stamped sheet metal layers and havea plurality of teeth 54 located around a periphery thereof. Each of thelayers include a shaft opening 51 so that the laminated sprocketassembly 50 can be mounted on a shaft. Here, as shown in FIG. 11, oilchannels 58 extend through at least some of the layers 53 from the shaftopening 51 to an oil opening on a periphery of the sprocket assembly 50.As shown in detail in FIGS. 12-14, preferably the oil channels 58include an oil exit opening 60 located on a side 55 of at least some ofthe teeth 54. The channels 58 are preferably defined as a slot thatextends through the layer 53. FIG. 13 shows one layer 53 including theslot stacked on top of a layer 52 that either does not include the slotor includes a slot rotated to a different radial position. In apreferred embodiment, the layers 53 which include the slot to form theoil channel 58 have an adjacent layer 52 that does not include a slotand therefore forms a solid disc rather than a slotted disc.Alternatively, layers 53 that include the slots can be located adjacentto one another with the slots rotated to different peripheral positions,for example as shown in FIG. 14. In the preferred embodiment, thechannels 58 extend generally radially and are spaced apart in theperipheral direction. While a single slot through a layer 53 is shown asforming one complete channel in FIGS. 12 and 13, it is also possible toprovide one channel 58 that extends from the shaft opening 51 to aperiphery of the laminated sprocket assembly 50 by slots defined in twoadjacent layers. For example, a slot in one layer can extend from theshaft opening part of the way to the periphery of the laminated sprocketassembly 50 while the slot in the adjacent layer can extend from thepart way position to the periphery. In a preferred embodiment, thechannel 58 has an opening 60 located in a side of a respective tooth 54and, preferably openings 60 of the channels 58 in a single sprocketassembly 50 are axially and peripherally spaced apart from one anotherin order to provide a generally uniform distribution of lubricationchannels 58 to the various peripheral areas of the laminated sprocketassembly 50 as shown in FIG. 14.

Having thus described the present invention in detail, it is to beappreciated and will be apparent to those skilled in the art that manyphysical changes, only a few of which are exemplified in the detaileddescription of the invention, could be made without altering theinventive concepts and principles embodied therein. It is also to beappreciated that numerous embodiments incorporating only part of thepreferred embodiment are possible which do not alter, with respect tothose parts, the inventive concepts and principles embodied therein. Thepresent embodiment and optional configurations are therefore to beconsidered in all respects as exemplary and/or illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description, and all alternateembodiments and changes to this embodiment which come within the meaningand range of equivalency of said claims are therefore to be embracedtherein.

What is claimed is:
 1. A laminated sprocket assembly, comprising: aplurality of layers that are connected together, each of the layersbeing a stamped sheet metal layer having a plurality of spaced apartteeth located around a periphery thereof, and the teeth in the pluralityof connected layers are aligned and in flat planar contact with eachother around the periphery; and recesses located in or between at leastsome of the layers for receiving lubricating oil, and the recesses arelocated on flanks of the teeth.
 2. The laminated sprocket assembly ofclaim 1, wherein each of the layers includes a shaft opening.
 3. Thelaminated sprocket assembly of claim 2, wherein aligned openings aredefined in each of the layers in a position spaced apart from the shaftopening and the teeth.
 4. The laminated sprocket assembly of claim 1,wherein the recesses are located in at least some of the layers in sidesof at least some of the teeth.
 5. A laminated sprocket assembly,comprising: a plurality of layers that are connected together, each ofthe layers being a stamped sheet metal layer having a plurality ofspaced apart teeth located around a periphery thereof, and the teeth inthe plurality of connected layers are aligned; and recesses located inor between at least some of the layers for receiving lubricating oil,the recesses are located in at least some of the layers in sides of atleast some of the teeth, and the layers on either side of the layerswith the recesses include teeth having side flanks without the recesses.6. The laminated sprocket assembly of claim 5, wherein the recesses areformed by a radius.
 7. The laminated sprocket assembly of claim 5,wherein each of the layers includes a shaft opening.
 8. The laminatedsprocket assembly of claim 7, wherein aligned openings are defined ineach of the layers in a position spaced apart from the shaft opening andthe teeth.